In trimming and/or testing electrical components (e.g., resistors) that are mounted on substrates, it is often desirable to support the substrates on a carrier and mount the carrier on an XY table. Movement of the XY table shifts test contacts and laser trimming beams from one component to the next. To allow the XY table to make rapid movements between components, the carrier must be lightweight and yet provide adequate retention for the substrates to prevent them from moving and becoming misaligned with the test contacts. The substrates come in many different sizes, are relatively fragile, and are generally tested in large quantities.